The CBSE Board has declared the CBSE 12th Board Exams Time Table 2025. The CBSE Class 12th Board Exams are set to be held from 15th February to 4th April 2025. Following the official CBSE 12th Exam Date Sheet 2025 the CBSE Class 12 Biology Exam 2025 is set to be conducted on 25th March 2025.
Biology is an important subject for students who have opted for the Science stream and aspire to make a career in medicine. Therefore, preparing well for the CBSE Biology Class 12 Exams 2025 will also increase the student's chances of clearing NEET (competitive exam for medicals) and actually excel in their career.
This year the Board has decided to include 50% knowledge and understanding based questions, 20% evaluation and analysis based questions, and 30% application based questions. In this article we have provided the most repeated topics from the two most important CBSE Biology Class 12 Units. Students must cover these topics thoroughly to ace the examination along with other topics. These units have the highest marks weightage in the CBSE 12th Biology Question Paper.
CBSE Class 12 Biology Unit 1: Reproduction
This unit teaches concepts and topics around reproduction in organisms (both plants and humans). The table below mentions the important topics for this unit along with their focus areas and question types asked:
| Topic | Key Areas/Focus | Common Question Types |
| Sexual Reproduction in Flowering Plants | - Microsporogenesis, megasporogenesis, and double fertilization. - Post-fertilization events (e.g., endosperm and embryo development). - Apomixis, polyembryony, and seed dispersal mechanisms. | Short-answer questions. |
| Human Reproduction | - Structure and functions of reproductive organs. - Gametogenesis (focus on oogenesis). - Menstrual cycle and hormonal regulation. | Analytical and assertion-reason questions. |
| Reproductive Health | - Contraceptive methods. - Population explosion. - Assisted reproductive technologies (ART). | Case-based or analysis-based questions. |
CBSE Class 12 Biology Unit 2: Genetics and Evolution
This unit covers topics revolving around inheritance principles, evolutionary theories, and molecular biology. The table below mentions the important topics for this unit along with their focus areas and question types asked:
| Topic | Key Areas/Focus | Common Question Types |
| Principles of Inheritance and Variation | - Mendelian inheritance, sex determination, and dihybrid crosses. - Pedigree analysis. - Incomplete dominance, codominance, and genetic disorders. | Numerical and application-based questions. |
| Molecular Basis of Inheritance | - DNA replication, transcription, translation, genetic code, and mutations. - Codon sequences, translational units, untranslated regions (UTRs). | Short- and long-answer questions. |
| Evolution | - Hardy-Weinberg principle, adaptive radiation. - Comparing theories of evolution. - Understanding evolutionary concepts through contrasting ideas. | Numerical and conceptual questions. |
How to score well in CBSE 12th Biology Exam 2025 ?
Students aspiring to score higher in the CBSE Class 12 Biology Exam 2025 need to focus on these topics and understand the concepts well. They should also prepare for application based questions. Students should also practice the CBSE 12th Biology sample papers and CBSE 12th Biology previous year question papers to prepare well for the exam.
